Correlative pairs of conjunctions include words like neither…nor, not…but, and both…and. For this punctuation rule, we can also consider sets of words like not only…but also. When pairs or sets of conjunctions are being used, they do not need to be separated from each other by a comma. However, a comma may be used between the conjunctions to accommodate another grammar rule (see Exceptions).
Either…or is a correlative pair of conjunctions. The comma should be removed from this sentence so the conjunctions are not separated from each other
Some common correlative conjunction sets include:
- either . . . or
- neither . . . nor
- both . . . and
- whether . . . or
- not only . . . but also
Commas Rarely Separate Correlative Conjunctions
Generally speaking, commas should not separate correlative conjunction pairs. Consider the following examples:
Exceptions Regarding Commas Between Correlative Conjunctions
As is the case with many grammar rules, there are exceptions to the rule regarding commas between correlative conjunctions. If the comma serves another grammatical function in the sentence, then it should be used, whether or not it separates parts of a correlative conjunction pair.
For instance, if commas are necessary to offset a nonrestrictive clause, then they may be used between the correlative pairs of conjunctions. Consider the example below:
Note that the correlative conjunction pair “neither . . . nor” is separated by the two commas necessary to offset the nonrestrictive clause “which paid only minimum wage.”
Commas may also separate correlative conjunction pairs when the comma separates two independent clauses with a coordinating conjunction. This is common with the correlative conjunction “not only . . . but also.” Look at the sentence below:
Note that when part of a correlative conjunction pair doubles as a coordinating conjunction, a comma precedes it. Moreover, the subject of the independent clause (in this case, “he”) also separates the “but” and “also” in this case.
Commas usually don’t separate pairs of correlative conjunctions, but there are exceptions.